The disclosure of U.S. Provisional Application No. 61/520,895, filed Jun. 16, 2011, is hereby incorporated herein in its entirety by reference.
Sickles typically including cutter bars supporting a row of knives, have been used to cut plants, including, but not limited to, hay, grasses, small grains and the like, for many years. The knives are composed of a plurality of knife or sickle sections which are mounted in side by side relation forming an elongate metal knife assembly. The elongate knife assembly is normally supported so as to slide longitudinally along an elongate stationary bar that has forwardly projecting, spaced apart guards bolted to a structural beam or knife back. The knife assembly moves back and forth in a reciprocating movement to move the knives relative to the guards so that the leading knife edges of the knives cross over the guards or through slots in the guards. This produces a shearing or cutting action which severs plant stems and stalks or other material captured between the knives and the guards.
In a harvesting machine, such as a combine or windrower, the knife assembly and stationary bar are typically supported in connection with a cutting head or header, and are oriented so as to extend sidewardly along a forward edge portion of structure such as a floor or pan of the header, hereinafter sometimes referred to generally as the floor. The floor or pan defines the lower periphery of a cut crop or plant flow area, which can include conveying apparatus, such as one or more augers or belts, operable in cooperation with a reel in machines so equipped, for conveying the cut plant material and crops, for instance, to a feeder inlet of a combine or windrow forming apparatus of a windrower.
Historically, many known sickle knife or cutter drive mechanisms have been located on the side end of the sickle, and connect to the knife assemblies utilizing connecting rods or Pitman arms, such as illustrated in Wanamaker U.S. Pat. No. 1,622,299, issued Mar. 29, 1927, and Boyer U.S. Pat. No. 2,332,840, issued Oct. 26, 1943. More recent known sickle drives are located in or below the floor or pan of a header or plant cutting machine, and are sometimes referred to as center drives or center knife drives, as shown in Priepke U.S. Pat. Nos. 7,810,304; 7,805,919; 7,730,709; 7,520,118; and 7,401,458, and Bich U.S. Pat. Nos. 8,011,272 and 8,151,547. Center knife drives such as these are advantageous as they are compact, and provide an efficient manner of translating epicyclic or crank motion to side to side knife motion.
A problem observed with the above center knife drives and other center drives such as pivotally driven drives, is that because of their location in or below the floor or pan, the drives are at least partially contained in a relatively low profile or flat housing or cover, on which loose crop material or residue and other undesirable material such as dust, dirt, and debris, can collect or accumulate. This is undesirable, as the material, if allowed to accumulate, can insulate the drive to reduce dissipation of heat generated by operation of the drive so as to possibly result in overheating and premature failure of drive components such as bearings.
As another problem, accumulated material can become lodged between the drive and underside of the floor or pan, and can even be compacted into a solid mass, so as to limit or prevent upward movement of the drive. This can be problematic, for instance, if the drive is used with a cutter bar and sickle that can flex upwardly, and wherein the sickle can be configured in a float mode so as to be movable upwardly toward the floor or pan. As another possible problem, some crop can be lost through openings or apertures of the floor or pan through which knife arms or other elements connecting with the knife assemblies pass.
Reference Rutishauser U.S. Pat. No. 1,567,013, which discloses an apparatus operable for preventing accumulation of material on a lever or knife arm of a sickle drive. The Rutishauser patent accomplishes this using a triangular distributing member that is pivoted back and forth over the lever to deflect and distribute the material cut by the sickle to the sides of the lever, which are open to allow the material to fall to the ground below. This keeps the cut material from collecting on the lever, but does not appear to have utility for preventing or substantially limiting passage of loose material through an opening or aperture in a floor of a plant cutting machine through which a side to side moving lever or knife arm extends.
As still another problem, the openings in a floor of a plant cutting machine through which the knife arms or levers driving a sickle extend, are typically located in a curved or tapered forward edge region of the floor or pan, so as to be at least partially forwardly facing, so as to be directly in the flow of cut crop and other loose material when the machine is moving forward during a plant cutting operation, and so as to be susceptible to having the loose material become trapped or jammed between the sides of the openings and the knife arms or levers which can cause increased stress loads on the drives and resultant wear and damage.
Thus, what is sought is a durable floor seal for preventing or limiting passage of loose material through an opening in a floor or pan of a plant cutting machine through which a knife arm or lever driving a sickle extends and moves in a side to side reciprocating manner, and which overcomes one or more of the problems set forth above.